The present invention relates to a lamp unit mounting structure in which a lamp unit is fitted to a lamp mounting window provided in an interior wall member and electric wires connected to the lamp unit are arranged on the interior wall member at a side of a vehicle body panel thereby to form a module, and the module is assembled to the vehicle body panel so as to cover the vehicle body panel, whereby the interior wall member and the lamp unit can be simultaneously assembled to the vehicle body panel.
Heretofore, there have been proposed lamp unit mounting structures in which an interior wall member such as a roof trim or a door trim covering a vehicle body panel and a lamp unit such as a room lamp or a courtesy lamp are simultaneously fixed to a vehicle body panel in order to decrease number of steps of an assembling (fixing) work in an assembly line of vehicles.
FIG. 7 is a longitudinal sectional view for explaining a related-art fixing structure of a room lamp which is disclosed in Japanese Patent Publication No. 2001-97112A.
In the fixing structure, a room lamp 1 and a roof trim 2 are provisionally fixed to each other by a provisional retainer 4, and at the same time, the room lamp 1 and a roof framework (reinforce) 3 of a vehicle body are plenarily fixed to each other by a plenary retainer 5, thereby allowing the room lamp 1 and the roof trim 2 to be simultaneously fixed to the roof framework 3.
The provisional retainer 4 include an engaging hook 14 provided on a side of the room lamp 1, and an engaging part 15 provided on a side of the roof trim 2.
The plenary retainer 5 provided on the room lamp 1 and the roof framework 3 include a spring 7 and a stopper 9 which are provided in the room lamp 1, and a fixing part 10 which is provided at an edge of a cut-out 13 formed in the roof framework 3.
The spring 7 made of a metal plate includes, as also shown in FIG. 8, an embedded portion 7a horizontally embedded in a lamp housing 11 of the room lamp 1, a first elastically deformable portion 7b folded diagonally upwardly from the embedded portion 7a in an L-shape, a second elastically deformable portion 7c folded diagonally downwardly from the first elastically deformable portion 7b in an inverted U-shape, a hook portion 7d folded substantially horizontally from the second elastically deformable portion 7c, and an operating portion 7e folded downwardly from the hook portion 7d in an L-shape.
When the room lamp provided with the fixing structure is intended to be fixed in a vehicle, as a first step, the engaging hook 14 at the side of the room lamp 1 is engaged with the engaging part 15 at the side of the roof trim 2 so as to provisionally fix the room lamp 1 and the roof trim 2 by the provisional retainer 4, prior to bringing them to an assembly line of the vehicle.
Then, a roof subassembly (a roof module) composed of the room lamp 1 and the roof trim 2 which have been provisionally fixed by the provisional retainer 4 is incorporated into the assembly line of the vehicle.
In this assembly line of the vehicle, the spring 7 at the side of the room lamp 1 is brought into elastic contact with the fixing part 10 at the side of the roof framework 3 in order to plenarily fix the roof subassembly composed of the room lamp 1 and the roof trim 2 to the roof framework 3 by the plenary retainer 5. On this occasion, the engaging hook 14 will not interfere with a horizontal part 18 of the roof framework 3, owing to provision of the cut-out 13 in the roof framework 3.
In this manner, with the fixing structure of the room lamp, the room lamp 1 and the roof trim 2 can be simultaneously fixed to the roof framework 3 in the assembly line of the vehicle, and as the results, the number of steps of the assembly work in the assembly line of the vehicle can be decreased.
However, there has been such an anxiety, in the related-art fixing structure of the room lamp as shown in FIGS. 7 and 8, that when the room lamp 1 and the roof trim 2 are plenarily fixed to the roof framework 3 by the plenary retainer 5, the hook portion 7d of the spring 7 may escape downwardly (toward an interior of the car) before the hook portion 7d of the spring 7 is set on the fixing part 10, as shown in FIG. 9A, and after an inner face (an upper face in the drawings) of the roof trim 2 has been abutted against a face of the roof framework 3 at the room side (a lower face in the drawings), the hook portion 7d may be unable to come into contact with the fixing part 10 of the roof framework 3, thus bringing the spring 7 in a half-fixed state.
Under the circumstances, in order to prevent the spring 7 from being brought into the half-fixed state as described above, it has been necessary to provide a clearance t, as shown in FIG. 9B, between the fixing part 10 and the hook portion 7d, when the inner face of the roof trim 2 is in contact with the room side face of the roof framework 3. However, in case where such a clearance t becomes too large, it is concerned that the subassembly may rattle due to vibration or so of the car while driving, and may generate strange noises.
Moreover, as far as the spring 7 of the retainer 5 is concerned, when the roof subassembly composed of the room lamp 1 and the roof trim 2 receives a strong external force which is exerted on the roof framework 3 toward the room side (downward in the drawings), there is such an anxiety that the fixation may be disengaged as shown in FIG. 9C, because the hook portion 7d is likely to be directed upward so that the holding strength is reduced.
It is therefore an object of the present invention to provide a favorable lamp unit mounting structure which is capable of assembling both a lamp unit and an interior wall member simultaneously to a vehicle body panel easily and reliably.
In order to achieve the above object, according to the present invention, there is provided a lamp unit mounting structure, comprising:
a panel body of a vehicle;
an interior wall member, which covers an interior side of the panel body; and
a lamp unit, including:
a first retainer, which engages with an exterior side of the interior wall member to retain the lamp unit on an interior side of the interior wall member;
a second retainer, which engages with an exterior side of the panel body to retain the interior wall member, on which the lamp unit is mounted, on the interior side of the panel body, the second retainer including a flexible arm having a free end portion which is flexible in a first direction parallel with the panel body and a second direction perpendicular to the panel body, the free end portion being abutted against the exterior side of the panel body when the interior wall member is mounted on the panel body; and
a regulator, which prevents the free end portion of the flexible arm from being flexed more than a predetermined amount in the second direction when the flexible arm is not flexed in the first direction.
According to the structure, when a module composed of the lamp unit mounted to the interior wall member is assembled to the vehicle body panel, the flexible arm is flexed into such a state as the free end portion can be engaged with or disengaged from the mounting part of the vehicle body panel.
On this occasion, the regulators will restrict the free end portion from being displaced in the direction in which the lamp unit is mounted to or detached from the vehicle body.
Therefore, when the lamp unit and the interior wall member are simultaneously assembled to the vehicle body panel as the module, the free end portion of the flexible arm will not escape to the interior of the vehicle in the direction in which the lamp unit is mounted to or detached from the vehicle body, before the free end portion is engaged with the mounting part of the vehicle body panel.
Therefore, the second retainer will be prevented from being brought into a half-fixed state in which the free end portion of the flexible arm is unable to be engaged with the mounting part of the vehicle body panel, and can securely assemble the module to the vehicle body panel. Further, since the free end portion of the flexible arm will not escape to the interior of the vehicle in the direction in which the lamp unit is mounted to or detached from the vehicle body, there will be no need of providing an excessive clearance with respect to the mounting part of the vehicle body panel taking this escape into account.
Furthermore, when the module which has been fixed receives a strong external force exerted on the vehicle body panel in a direction to the interior of the vehicle, the flexible arm whose free end portion is restricted from being displaced in the direction in which the lamp unit is mounted to or detached from the vehicle body will not be disengaged from the fixed state, because the distal end portion will be prevented from being directed upward.
Preferably, the regulator includes a wall portion extending in the first direction, and the flexible arm includes a pair of projections arranged in the second direction such that the wall portion is fitted therebetween.
Here, it is preferable that the regulator includes a guide slope on which the projections of the flexible arm are slidable so that the free end portion of the flexible arm is allowed to be flexed more than the predetermined amount in the second direction when the flexible arm is flexed in the first direction.
In this case, when the module is assembled to the vehicle body panel, the free end portion will be flexed by the guide slope having the sliding guide face, into such a state as the free end portion can be engaged with or disengaged from the mounting part of the vehicle body panel, and at the same time displaced toward the vehicle body panel.
As the results, the free end portion of the flexible arm can be securely engaged with the mounting part of the vehicle body panel, even though there is no clearance provided with respect to the mounting part of the vehicle body panel when the assembly to the vehicle body has been completed. Further, since an elastic repulsive force can be created in the flexible arm when the assembly to the vehicle body has been completed, the module will be prevented from rattling with respect to the vehicle body panel.
Preferably, the lamp unit includes an elastic piece which is elastically abutted against the interior side of the panel body when the interior wall member is mounted on the panel body.
In this case, the module will be prevented from rattling with respect to the vehicle body panel.